Coronavirus data used in decision to reopen Georgia flawed

ATLANTA (AP) — Data on coronavirus infections that was a key driver in Georgia Gov. Brian Kemp’s aggressive push to reopen the state was flawed and may have distorted perceptions of progress against the virus.

Georgia Department of Public Health spokeswoman Nancy Nydam said in an emailed statement Thursday that the department included antibody tests when calculating the total number of tests conducted “since early April.” She said about 57,000 of the 407,000 total tests reported to the state have been antibody tests.

The inclusion of antibody tests in state testing data was first reported by the Columbus Ledger-Enquirer.

Antibody tests look for the presence of a protein that the body makes in reaction to the virus, while other, more common tests, called viral tests, look for the virus itself.

Conflating the two tests can create confusion about the current impact of the virus, said Dr. Richard Rothenberg, an infectious disease expert at Georgia State University. That’s because antibody tests tell you whether a person had the coronavirus in the past, not whether the person was infected at the time of the test.

Combining them can create “a false impression of what is happening now,” he said. He also noted that antibody tests made up about 15% of the total tests — a figure that he said would make a “substantial impact” on the perception of the outbreak.

Kemp relied on the state seeing a downward trajectory of the percentage of positive tests when making his decision to be one of the first states in the nation to allow business to reopen. Salons, restaurants, gyms and other businesses in Georgia were given the green light to reopen in April.

News outlets report that the health department is not counting positive antibody tests when calculating the total number of positive confirmed cases in the state. That would artificially downplay the percentage of positive tests, the metric Kemp has heavily leaned on to make decisions about reopening.

Nydam did not answer questions sent by email, including a question about how positive antibody test results are recorded when the state calculates the percentage of positive tests, but sent a statement in reply. The statement says that DPH “is currently working diligently to provide greater transparency” in the data it makes public, including splitting out the reporting of antibody tests from viral tests.